Minnesota Center for Environmental Advocacy et al. v. Trump et al.

On July 17, 2025, President Trump issued a proclamation exempting the entirety of the taconite iron ore processing industry from the 2024 updated National Emission Standards for Hazardous Air Pollutants for Taconite Iron Ore Processing (taconite rule). These standards protect communities living and working near these facilities from exposure to toxic air pollutants, including mercury and acid gases. Mercury is a neurotoxin linked to IQ loss, deficiencies in attention span and motor function, and developmental disorders in fetuses and young children. Exposure to acid gases leads to heart attacks, aggravated asthma, and other respiratory effects. The U.S. Environmental Protection Agency (EPA) predicted that the taconite rule would reduce mercury exposure by 247 pounds per year and acid gas emissions by 719 tons per year. The EPA issued this rule in part to comply with a District of Columbia Circuit decision requiring the agency to set standards for previously unregulated hazardous air pollutants—here, mercury—emitted by a major source category when conducting its technology review. Without the taconite rule, there are no federal emissions limits on mercury from taconite ore processing.  

President Trump’s proclamation unilaterally sweeps away those protections for all taconite ore-processing facilities. The facilities, each owned by one of two multibillion-dollar corporations—U.S. Steel and Cleveland-Cliffs—have a free pass to continue to pollute and put communities at risk for two more years. It has been more than 20 years since the EPA acknowledged in court its legal obligation to issue a mercury standard for this industry. Now, the Trump administration’s action allows mercury emissions to go unchecked for an additional two years.  

Already, taconite facilities account for nearly half of all mercury emissions in Minnesota, and the EPA has acknowledged record evidence linking mercury deposition in the Upper Great Lakes region to fish consumption advisories and adverse impacts on wildlife and human health. 

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To exempt these facilities, the Trump administration exploited a narrow and, until this year, never-before-used provision of the Clean Air Act. Section 112(i)(4) of the act provides authority to exempt sources from a hazardous air pollutant standard if the president determines that the technology to implement the rule is “not available” and that an exemption is in the national security interests of the United States. But the Trump proclamation does not provide any evidence that the technology is not available—because it is. The air pollution control technology needed to comply with the standards has been pilot tested by taconite facilities and long been used in other industries to effectively reduce mercury emissions. The EPA estimated that taconite ore processing facilities would be able to comply with these standards with limited new installation and add-on controls. 

What makes this free pass particularly appalling is the indiscriminate, unjustified nature of the exemptions. In a blatant end run around administrative procedures, the proclamation exempts the entire industry, in direct contradiction to the EPA’s scientific and technical findings from just a year ago. The proclamation even applies to the Empire mining facility in Ishpeming, Michigan, a facility that is idle and has no plans to resume operations. 

President Trump’s abuse of Section 112(i)(4) is not just limited to taconite facilities. In April and July of 2025, he exempted nearly one-third of coal-fired power plants from mercury and air toxics standards; nearly one-quarter of chemical manufacturers from hazardous air pollution standards; almost half of all commercial medical sterilizers from ethylene oxide standards; one of two U.S. copper smelters; and the entire coke ovens industry from benzene, mercury, and acid gas standards. With the stroke of a pen, President Trump has wiped away hazardous air pollutant rules for more than 180 facilities across these six industries. 

President Trump’s exemptions of taconite ore processors from regulations of hazardous air pollutants not only sacrifice the health of communities, but they are also illegal and undemocratic. Never before has a president claimed the authority to mass exempt from EPA regulations—rules that were issued just two years ago after extensive scientific and technical review and full public notice and comment.  

NRDC and the Minnesota Center for Environmental Advocacy have filed suit in the D.C. District Court to challenge this ultra vires and illegal exemption.